ultrafaint_dwarf_galaxy_search

notebooks/MAST/dwarf_galaxy_search/requirements.txt

@@ -0,0 +1,4 @@
+astroquery>=0.4.6
+numpy>=1.22.3
+matplotlib>=3.5.1
+Jdavis>=3

notebooks/MAST/dwarf_galaxy_search/solutions_exercise_dwarf_galaxy_search.ipynb

@@ -0,0 +1,173 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "b6ab59f6",
+   "metadata": {},
+   "source": [
+    "# Solution to Exercise in ultrafaint_dwarf_galaxy_search.ipynb\n",
+    "\n",
+    "## 1. Plot Field of View of Draco II \n",
+    "\n",
+    "Can you recreate the steps we took for **Leo I** to plot the field of view of **Draco II** in black and white and in color?  \n",
+    "\n",
+    "### Start by building the url to the fits file of the region for our target"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "1199c638",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#read RA and Dec from either SIMBAD or Table 1 in Laevens et al 2015\n",
+    "r = '15:52:47.6'\n",
+    "d = '+64:33:55'\n",
+    "\n",
+    "#Convert the RA and Dec to degrees\n",
+    "c = SkyCoord(r+d, unit=(u.hourangle, u.deg))\n",
+    "ra = str(c.ra.degree)\n",
+    "dec = str(c.dec.degree)\n",
+    "\n",
+    "filters = \"grizy\"\n",
+    "size = \"240\" #extracted image size in pixels (0.25 arcsec/pixel)\n",
+    "form = \"fits\" #file format of the file we would like\n",
+    "\n",
+    "color = \"red\" #you can change this, red is typically the i or r filter\n",
+    "\n",
+    "#get the url to the PS1 images\n",
+    "images_url = \"https://ps1images.stsci.edu/cgi-bin/ps1filenames.py?ra=\"+ra+\"&dec=\"+dec+\"&filters=\"+filters\n",
+    "#read the images data into a table\n",
+    "img_table = Table.read(images_url, format='ascii')\n",
+    "\n",
+    "#get the first filename from the list of images\n",
+    "file = img_table['filename'][0]\n",
+    "\n",
+    "#build the url to the fits file\n",
+    "fits_url = \"https://ps1images.stsci.edu/cgi-bin/fitscut.cgi?ra=\"+ra+\"&dec=\"+dec+\"&size=\"+size+\"&format=\"+form+\"&\"+color+\"=\"+file\n",
+    "\n",
+    "print(fits_url)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "88629e31",
+   "metadata": {},
+   "source": [
+    "### Open the fits file and plot the image\n",
+    "\n",
+    "Here we will plot the field of view containing our UFD, Leo I. Remember, it is Ultra-Faint!\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "c325c0f2",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#open the fits file and get the data\n",
+    "fh = fits.open(fits_url)\n",
+    "fits_img = fh[0].data\n",
+    "\n",
+    "# replace NaN values with zero for display\n",
+    "fits_img[np.isnan(fits_img)] = 0.0\n",
+    "\n",
+    "#show the fits image\n",
+    "plt.imshow(fits_img,cmap=\"gray\",origin=\"lower\")\n",
+    "plt.title(\"Draco II - PS1 i\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "910d4f49",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "1e23ec4a",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#make a stacked color image by combining filters\n",
+    "filters = \"grizy\"\n",
+    "size = \"240\" #extracted image size in pixels (0.25 arcsec/pixel)\n",
+    "form = \"fits\" #file format of the file we would like\n",
+    "\n",
+    "red = \"red\" #you can change this, red is typically the r or i filter\n",
+    "blue = \"blue\"\n",
+    "green = \"green\"\n",
+    "\n",
+    "#get the url to the PS1 images\n",
+    "images_url = \"https://ps1images.stsci.edu/cgi-bin/ps1filenames.py?ra=\"+ra+\"&dec=\"+dec+\"&filters=\"+filters\n",
+    "#read the images data into a table\n",
+    "img_table = Table.read(images_url, format='ascii')\n",
+    "\n",
+    "#get the first filename from the list of images\n",
+    "file = img_table['filename'][0]\n",
+    "\n",
+    "#build the url to the fits file\n",
+    "red_fits_url = \"https://ps1images.stsci.edu/cgi-bin/fitscut.cgi?ra=\"+ra+\"&dec=\"+dec+\"&size=\"+size+\"&format=\"+form+\"&\"+red+\"=\"+file\n",
+    "blue_fits_url = \"https://ps1images.stsci.edu/cgi-bin/fitscut.cgi?ra=\"+ra+\"&dec=\"+dec+\"&size=\"+size+\"&format=\"+form+\"&\"+blue+\"=\"+file\n",
+    "green_fits_url = \"https://ps1images.stsci.edu/cgi-bin/fitscut.cgi?ra=\"+ra+\"&dec=\"+dec+\"&size=\"+size+\"&format=\"+form+\"&\"+green+\"=\"+file\n",
+    "\n",
+    "\n",
+    "print(fits_url)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "fa39a1e9",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#open the fits file and get the data\n",
+    "fh_red = fits.open(red_fits_url)\n",
+    "fh_blue = fits.open(blue_fits_url)\n",
+    "fh_green = fits.open(green_fits_url)\n",
+    "\n",
+    "red_fits_img = fh_red[0].data\n",
+    "blue_fits_img = fh_blue[0].data\n",
+    "green_fits_img = fh_green[0].data\n",
+    "\n",
+    "# replace NaN values with zero for display\n",
+    "red_fits_img[np.isnan(red_fits_img)] = 0.0\n",
+    "blue_fits_img[np.isnan(blue_fits_img)] = 0.0\n",
+    "green_fits_img[np.isnan(green_fits_img)] = 0.0\n",
+    "\n",
+    "#show the fits image\n",
+    "plt.imshow(green_fits_img,cmap=\"Greens_r\",origin=\"lower\", alpha = 0.35)\n",
+    "plt.imshow(red_fits_img,cmap=\"Reds_r\",origin=\"lower\", alpha = 0.45)\n",
+    "plt.imshow(blue_fits_img,cmap=\"Blues_r\",origin=\"lower\", alpha = 0.25)\n",
+    "plt.title(\"Draco II - PS1 r,g,i\")"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.8"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}